Video Resolution: The app will save in the best possible format, highest resolution for your iPhone, that means that if you have a video that is 4K it will save as 4K providing your iPhone is 6s, 6s+,7, 7+ or newer. But if your phone is older it will be saved in just the best possible resolution.

This app will not resize up your video, so if your original video is 720p it will remain with that size.